The cost of funding the Post-2015 Development Agenda is estimated to be trillions of dollars a year.1 Whilethis magnitude may seem dizzying, especially for low-income countries with over-stretched public budgetsand donor countries facing economic uncertainties, the financial resources required are in fact available.2It is a matter of setting the right priorities, ensuring equitable distribution, and avoiding the mistakes andomissions of the past. And while the questions abounding are ‘who will pay and how?’, research showsthe high rewards from smart investments in key areas. Meanwhile, the costs of inaction far outweigh theresources required to make sustainable, people-centered development and a healthy planet a reality.